Best underwear...

I'm thinking well ahead to my september 2025 wedding, but just wondering what to wear under my dress. I don't want to feel too constricted but do feel I'll need something smoothing. Also I'm not sure control underwear can be hidden by my dress. Just wondering whether Skims are worth it. I have a bit of tummy that I'm conscious of but definitely don't want to lose any weight so thinking a good pair of control underwear might be the answer but want to be comfortable so I can enjoy all the great food we're paying for haha!